Update packages

 sudo apt-get update

Install nginx

sudo apt-get install nginx

Check version

 nginx -v

How to add personal domain

Go to the domain website and add the dns as AWS instace Ip address

Run nginx

 sudo nginx

 sudo nginx -s reload

After this nginx running on ip address

Config Nginx to run the website on domain and works without writing :portNumber

Path : /etc/nginx/sites-available/default

server_name aman-meenia.work.gd, www.aman-meenia.work.gd;

 location / {
               server_name aman-meenia.work.gd, www.aman-meenia.work.gd; # First attempt to serve request as file, then
                # as directory, then fall back to displaying a 404.
                 proxy_pass http://localhost:3000;
                proxy_http_version 1.1;
                proxy_set_header Upgrade $http_upgrade;
                proxy_set_header Connection 'upgrade';
                proxy_set_header Host $host;
                proxy_cache_bypass $http_upgrade;

        }

To test config is correct or not

sudo nginx -t

Reload

sudo nginx -s reload

SSL certificate using certbot

 sudo apt install certbot python3-certbot-nginx

For what domain you want ssh certificate

 sudo certbot --nginx -d next-auth.work.gd -d www.next-aut.work.gd

Renew certificate automatically

sudo certbot renew --dry-run

Anotherw way for free ssl

sudo snap install core; sudo snap refresh core

sudo apt remove certbot

sudo snap install --classic certbot

sudo ln -s /snap/bin/certbot /usr/bin/certbot

sudo certbot --nginx -d app.example.com 

Verify Certbot Auto-Renewal

sudo systemctl status snap.certbot.renew.service

To test the renewal process, you can do a dry run with certbot:

sudo certbot renew --dry-run

Proxy_http_version 1.1;

This specifies the HTTP version that Nginx should use when communicating with the upstream server (your app). HTTP/1.1 supports features like persistent connections and chunked transfer encoding, which are often required for modern web apps.

proxy_set_header Upgrade $http_upgrade;

This line ensures that the `Upgrade` header from the client is passed along to the upstream server. This is crucial for handling WebSocket connections, which rely on the `Upgrade` header to switch from HTTP to the WebSocket protocol.

proxy_set_header Connection 'upgrade';

Similar to the `Upgrade` header, this sets the `Connection` header to `'upgrade'`. This header is also essential for WebSocket communication, ensuring that the connection can be upgraded from HTTP to WebSocket.

proxy_set_header Host $host;

This directive passes the original `Host` header from the client to the upstream server. The `$host` variable dynamically captures the domain name or IP address that the client used to access the server, ensuring that the upstream server receives the correct `Host` header.

proxy_cache_bypass $http_upgrade;

This setting tells Nginx to bypass its caching mechanisms if the `Upgrade` header is present in the request. This is necessary for WebSocket connections to function correctly, as caching can interfere with the real-time communication required by WebSockets.